Admittedly for all the bike trips I've taken over the years or even part-cycling trips lasting over several weeks, I'm not overly vigilant about what I eat and how much.

I stayed the same weight after 4 weeks in Europe. This included several large buffet breakfasts, some lovely cake slices and coffee breaks during the trip, etc.

I did deliberately scale down some (not all) of my suppers if I had a particularily large breakfast, avoid deep fried food where possible.

During the four weeks, only had about 3 day trips where each trip was around 90 kms. each. Other cycling averaged 15-30 kms. per ride. I skipped some days and did not cycle at all.

What are your eating habits like when cycle touring or vacationing where some days you are cycling for several hrs.?